In the process of production of a liquid crystal display, organic EL display, plasma display, or other flat panel display or a semiconductor, usually, patterns of a photosensitive composition are formed using photolithography.
As the methods of forming patterns of RGB or a resin black matrix in production of a color filter used for a liquid crystal or organic EL display, pigment dispersion, dyeing, printing, electrodeposition, and the like methods are used. Pigment dispersion is a method of patterning of colors by photolithography using photosensitive compositions containing pigments. As stable colored films are obtained, this method is suitable for production of a color filter. When using this method to form a photosensitive composition film on a substrate, there is a process of coating the substrate with a photosensitive composition containing a pigment. As the coating method, spin coating, slit coating, wire bar coating, roll coating, dip coating, spray coating, or a combination thereof or other methods are known.
In spin coating, the swelling parts of the photosensitive composition film at the periphery and edges of the substrate or the photosensitive composition deposited on the back of the substrate after coating the photosensitive composition is normally removed by rinsing by a photosensitive composition remover, that is, so-called edge rinsing or back rinsing. Further, in spin coating, in the process of removing the photosensitive composition splattering in a cup, that is, cup rinsing, as well, treatment is performed to remove the photosensitive composition by a photosensitive composition remover.
Further, as a process for coating a photosensitive composition in the production of a color filter, in addition to the above spin coating, there are coating of a photosensitive composition by slit coating, coating using a wire bar, and coating by a roll coater. In these methods as well, unnecessary photosensitive composition deposited on all or part of the slit nozzle, wire bar, or other parts of the coating system is removed after coating the photosensitive composition. Further, in addition, sometimes the photosensitive composition deposited on members of the coating system, such as the system piping for transporting the photosensitive composition, is removed as well. Normally, for this removal of the photosensitive composition, a remover is used for cleaning.
In any of the processes for removal of a photosensitive composition deposited on a substrate or system, the remainder of the photosensitive composition component becomes a problem. With the photosensitive compositions containing pigments used for the production of a color filter, that is, the color resists used for formation of RGB or the black resist used for formation of a resin black matrix, the pigment components easily remain on the substrate or system surface. Even if these are slight, foreign matter may cause an increase in the defect rate in the production of color filters or a change in the color purity of the color filters or a drop in the contrast. There is growing demand for increasing the size and definition and lowering the cost of the substrates for the color filters used for color displays in recent years. In view of this situation, avoiding residual photosensitive composition components affecting the performance and yield of the color filters is becoming increasingly important.
In the past, as the remover for a photosensitive composition, a glycol ether or its ester or a mixture thereof has generally been used (for example, see Japanese Examined Patent Publication (Kokoku) No. 4-49938), but when applying this for cleaning off the above color resist, the removability of the resist is not sufficient, use of a large amount of remover becomes necessary, or incomplete removal results.
Further, for removal of a colored composition containing a pigment, there is also the method of using the solvent component used for the photosensitive composition or the component contained in the photosensitive composition such as a surfactant or dispersant (for example, see Japanese Unexamined Patent Publication (Kokai) No. 2000-273370), but when using only the solvent component contained in the photosensitive composition as a cleaner, the pigment easily precipitates and sufficient cleanability cannot be obtained. Further, when incorporating a surfactant, dispersant, or other component contained in the photosensitive composition in the cleaner composition, the component easily remains as a residue after evaporation on the substrate or system members, a further cleaning process becomes necessary, and use for removal of the photosensitive composition at the end faces and back of a substrate where remainder of a residue after evaporation is not preferred becomes impossible in practice.